20-320mW 5.5V 405nm Blue-violet Laser Diode Driver / Blue-Violet Light Boost Circuit 9*20mmDriver Specifications:Circuit control: 5.5V step-up Circuit, constant voltage outputSize:9*20mm (WxL)Reverse polarity protection included.QSP protection: protection with soft start, even if you frequently switch power you will not worry about damaging the laser tubePin definition: designed pad especially for 405nm with a PD function of the driver board, you just need to solder pins on the triangle to the natural order, not the same as the other board, to cut off one foot, or staggered welding!Polarity Definition: module shell is positive, negative tail padRecommend to use 3.7V lithium battery (16340, 18650, 14500 and 18500 power supply), or directly using 5.5V DC power supply.Package: 1pcPayment1. Payment method on ESCROW2. Credit Card3.4. Other payment modes etc on Ali-express supportShipping & DeliveryThere are two methods of shipping for you to choose when you check out. The free shipping is Air Mail (postal service), the postal system will make the delivery. The Express shipping is EMS, DHL or UPS. We will choose the company for you depending on their service availability.1. The default shipping service for all items over $10 is China Post or Hong Kong Post Air Mail with a tracking number: a tracking number is used for mail status tracking and it is insurance at the same time. Order under $10 will not have such a tracking number.2. You can track your mail though national post within 3 days after the payment and a tracking number is provided by item status notification email from laserlands. For example: US USPS. We will send the tracking number to your via your email .3. Within 3 business days for domestic handling time once cleared payment received.